Method and apparatus for measuring and adjusting the setting of a crusher

ABSTRACT

A method and apparatus are disclosed for measuring and monitoring the setting of a crusher, in which method the erosion of the wearing parts of the crusher are monitored by sensors capable of transmitting the measurement data to the crusher&#39;s automatic control system. Based on the received measurement data, the control system adjusts the crusher setting so as to maintain the setting at its predetermined value irrespective of the erosion of the crusher&#39;s wearing parts. The invention also relates to alternative embodiments of wear sensors for the wearing parts of a crusher. The measurement data indicating the amount of erosion in the wearing parts is transmitted wirelessly to the exterior side of the crusher.

The invention relates to crushers. More specifically, the inventionrelates to the measurement and adjustment of the setting of a crusher sothat the set position of the setting of the crusher can be maintainedconstant irrespective of the erosion of the crusher's wearing parts. Theinvention also relates to alternative embodiments of wear sensors forthe erosion indication of the wearing parts of a crusher.

Cone crushers have a vertical eccentric shaft with an inclined innerbore made thereto. Into the bore is fitted the main shaft of thecrusher, generally having a support cone mounted thereon. The supportcone is surrounded by the crusher frame having mounted therein an outerwearing member, generally known as the bowl liner. Respectively, ontothe support cone is mounted another, inner wearing member, generallyknown as the head liner. The head liner and the bowl liner define acrusher chamber wherein the crushing of the infeed material takes place.With the rotation of the eccentric shaft, the main shaft as well as thesupport cone therewith are set into an oscillatory motion, whereby thegap between the head and the bowl at any give point therebetween variesduring each rotation. The minimum gap width during one full rotation iscalled the crusher setting and, respectively, the difference between thegap width maximum and minimum is called the crusher stroke. By adjustingthe crusher setting and stroke, as well as the rotating speed of thecrusher, it is possible to modify such operating variables as theparticle size distribution of the crushed rock and the productioncapacity of the crusher.

Often also the upper end of the crusher main shaft is supported to thecrusher frame by an upper support bearing. Hence, this type of conecrusher is generally known as a gyratory crusher.

A gyratory crusher is generally made adjustable by means of a hydraulicsystem that permits the main shaft to be movable in the verticaldirection in regard to the crusher frame. As a result, the crushersetting may be varied so that the particle size of the crushed rockmeets the particle size specification of the current order and/or thecrusher setting is maintained constant irrespective of the wear of thecrusher liners.

In other types of cone crushers, the crusher setting adjustment mayalternatively take place by elevating or lowering the crusher upperframe with the crusher head mounted thereto in regard to the crusherlower frame and the main shaft whose vertical position in regard to thecrusher lower frame is fixed.

In impact crushers, the crushing of the infeed material takes placebetween a rotating rotor equipped with breaker bars and breaker platesmounted on the interior walls of the crusher frame. This kind of crusherhas a plurality of breaker plates placed at different distances from therotor so that a gradual reduction of the infeed material to be crushedis obtained. The crusher setting that controls the final aggregate sizeof the crushed rock is determined by the set position of the lastbreaker plate in the travel direction of aggregate material through thecrusher. To protect the breaker plates, wearing elements are attached onthose outer areas of the breaker plates that act as the crushingsurfaces.

Impact crushers may have a horizontal or vertical construction.

In jaw crushers, the crushing cavity comprises two opposed jaws, ofwhich one is fixedly mounted on the crusher front frame while the otherjaw is a movable jaw connected to an oscillating element called apitman, together with side plates that join the front frame of thecrusher to its rear frame. The crushing cavity formed between thecrushing jaws is a downward tapering gap, whereby the distance betweenthe lower edges of the jaws is called the crusher setting. Through theeye of the pitman is passed an eccentric shaft that is mounted inbearings on the crusher side plates and the pitman. The eccentric shaftis connected to a flywheel rotated by external drive machinery. With thehelp of the eccentric shaft, the movable jaw connected to the pitman isforced to perform a substantially elliptic crushing motion in regard tothe fixed jaw. Generally, the setting of a jaw crusher is adjusted bymeans of setting adjustment wedges which are adapted to the crusher rearframe so that sliding the wedges against a toggle plate inside thecrusher rear frame causes the position of the lower edge of the movabledie plate to shift in regard to the crusher rear frame and, thus, inregard to the fixed jaw. Also other kinds of setting adjustments areknown, one of such being disclosed in patent publication U.S. Pat. No.4,927,089.

However, no technology is available today for monitoring the actualvalue of crusher setting. Conventional technology offers only facilitiesfor monitoring the mutual position of crusher parts related to crushersetting adjustment and support of wearing parts. This information,however, is not sufficient to facilitate the automation of the crushersetting adjustment inasmuch as neither the actual thickness of thewearing part nor its wear rate can be determined. Conventionally,compensation of wear has been carried out by first performing scheduledinspections of crushing wearing parts and, as a result thereof, thenestimating the future need for setting adjustment. Due to widevariations of rock type even in a single quarry, this approach has notproven particularly reliable.

In patent publication U.S. Pat. No. 6,129,297 is disclosed one method ofmonitoring the progress of wear in the wearing parts of a crusher.According to this invention, on the rear surfaces of the wearing partsin the crusher are made recesses reaching up to a depth that representsthe maximum allowable degree of wear of the wearing parts in thecrusher. The recesses are filled with a suitable material such as acolor composition. When the erosion of the wearing parts eventuallyreaches a point that reveals the recesses, the color composition spreadsonto the surfaces of the wearing parts of the crusher, wherefrom thewear indication is easy to detect by the crusher operator. However, thiskind of arrangement fails to provide on-line wear information duringcrushing inasmuch as the crusher must always be stopped for inspectionthus causing losses in production capacity. Moreover, the embodimentaccording to cited publication invariably involves a risk of operatorsafety, since the crusher operator must climb onto the crusher to seewhether the color composition is already visible in the crushingchamber. Hence, this kind of arrangement does not offer real-timemonitoring of the erosion of wearing parts as it only indicates theterminal point at which the wearing parts of a crusher must be replaced.

Sensors suitable for condition monitoring of wearing parts in crushersare known in the art from patent publications DE 43 12 354 and DE 43 08272, wherein the function of disclosed wear sensors is based on anelectrical circuit comprising series-connected resistors. The wearingportion of the sensors incorporate conductors that break with theerosion of the wearing part thus either increasing or decreasing theresistance of the sensor circuit.

In patent publication FI 96924 is disclosed a gyratory crusher hydrauliccontrol system having a hydraulically supported main shaft. Herein, thecrusher setting can be adjusted by controlling the amount of hydraulicfluid pumped into a cylinder situated at the lower end of the mainshaft, whereby the main shaft together with the head cone mountedthereon is elevated/lowered in regard to the crusher frame.

The method according to claim 1 and apparatus according to claim 3 nowdisclose an arrangement for measuring and monitoring the set position ofa crusher during crushing, whereby also sensors for measuring the amountof erosion in the wearing parts of a crusher are disclosed in claims 9,11 and 16.

In the method according to the invention, the erosion of wearing partsin a crusher is measured on-line during the operation of the crusherthus allowing the setting of the crusher to be controlled to a constantvalue irrespective of the erosion of the wearing parts.

The apparatus according to the invention facilitates real-time wearmonitoring of crusher wearing parts with the help of wear sensorsinstalled therein. Subsequently, the measurement data indicating thedegree of wear in the crusher wearing parts is transmitted to the alarmsystem or automatic control system of the crusher. Also the crushersetting adjustment means are provided with sensors capable of measuringthe position of the support surfaces of the crusher wearing partsrelative to each other. Subsequently, also the measurement dataindicating the relative positions between the support surfaces of thecrusher wearing parts is transmitted to the automatic control system ofthe crusher. With the help of the measurement data indicating the wearsituation of the crusher wearing parts and the measurement dataindicating the relative position between the support surfaces of thecrusher wearing parts, the crusher's automatic control system adjuststhe position of the support surfaces of the crusher wearing parts thusmaintaining the crusher setting constant irrespective of the wear of thecrusher wearing parts.

In the apparatus according to the invention, information transmissionmay alternatively be advantageously implemented by wireless techniques.Herein, the thickness sensor of the wearing part is complemented withmeans for wireless transmission of information to the exterior of thecrusher, whereby the external control system includes means forreception of the transmitted information. This kind of sensor system mayalso be complemented with an integral power supply generating theelectrical energy required in the operation of the system, thus allowingthe sensor system to be advantageously constructed into a self-containedentity incorporated in the wearing part of the crusher so as to movetherewith. As a result, problematic wiring for information transmissionand power feed can be disposed with.

Power feed for the sensors may be implemented using a battery, forinstance. Alternatively, electricity for the sensors may also begenerated from the motion of the crusher wearing parts with the help ofa device that converts kinetic energy into electric energy. Sucharrangements are known from wristwatches, for instance. The necessaryelectric energy may also be produced with a piezoelectric device orcaptured by means of, e.g., RF techniques from an electromagnetic fieldsurrounding the crusher.

In its simplest configuration, the information gathered by the apparatusaccording to the invention is employed as the input information to thealarm system of the crusher, whereby the crusher operator is warned bythe alarm system when the wearing parts of the crusher are about to runout.

One embodiment of a sensor developed for use in the apparatus accordingto the invention comprises a resistor network embedded in a wearing partof the crusher such that the resistance of the resistor network changeswith the erosion of the wearing part thus delivering a measurementsignal that changes with the amount of erosion.

The wear sensor outlined above facilitates the measurement of wearingparts in real time without calibration operations. Based on the degreeof wearing parts wear computed from the wear measurement data, thesetting of the crusher can now be identified more accurately than in theprior art. Simultaneously, also the wear monitoring of the crusherwearing parts (e.g., in percent), estimation of the wear rate and needfor replacement at the end-life of the wearing parts may be reliablycarried out. Patent application FI 20010673 discloses a data gatheringsystem suitable for automatically issuing a replacement order for awearing part on the basis of the information obtained from a sensor.

The wear of a crusher wearing part may alternatively be monitored byacoustic means using, e.g., an ultrasonic sensor. Herein, the amount oferosion is detected by way of utilizing the reflective properties of theouter surface of the wearing part.

Still further alternatively, a strain gage can be used as a sensor,whereby the deformation of the wearing part due to its erosion isutilized to determine the amount of erosion.

The wear monitoring and control system according to the invention isable to maintain a constant setting of a crusher thus assuring a uniformquality of the final product from the crusher. The system is easy tomanage as compared with a conventional arrangement and, moreover, wearinformation can be retrieved readily and safely without needing theoperator to climb onto the crusher. Measurement takes place continuallywithout any shutdown in production. This allows the wearing parts of thecrusher to be exploited “down to the last inch” without the fear ofwear-out of the wearing parts and a resultant damage to the crusher.Based on the information delivered by the system, the user can establishan automatic ordering system of spare parts that gives an additionalbenefit of an optimized spare parts inventory. Moreover, variations inthe erosiveness of the infeed material will not cause unexpectedsurprises.

More specifically, the method according to the invention ischaracterized by what is stated in the characterizing part of claim 1,the apparatus according to the invention is characterized by what isstated in the characterizing part of claim 3 and the wear sensors andwear sensor instrumentation according to the invention are characterizedby what is stated in the characterizing parts of claims 9, 11 and 16.

In the following, the invention will be examined in more detail bymaking reference to the appended drawings in which

FIG. 1 shows a typical prior-art gyratory crusher equipped with wearsensors according to the invention;

FIG. 2 shows a typical prior-art cone crusher equipped with wear sensorsaccording to the invention;

FIG. 3 shows a typical prior-art impact crusher equipped with wearsensors according to the invention;

FIG. 4 shows a typical prior-art jaw crusher equipped with a controlsystem according to the invention;

FIG. 5 shows the structure of the wearing portion of a wear sensoraccording to the invention;

FIGS. 6 and 7 show exemplary embodiments of the location of ultrasonicsensors in the wearing part of a crusher; and

FIGS. 8 and 9 show exemplary embodiments of the location of strain-gagesensors in a wearing part of a crusher.

Referring to FIG. 1, the main components of the crusher shown thereincomprise a lower frame 1, an upper frame 2, a main shaft 3, a supportcone 4, an outer liner 5, an inner liner 6, a crushing chamber 7, adrive shaft 8, an eccentric shaft 9 and a control cylinder piston 10.

The crusher frame comprises two main units: a lower frame 1 and an upperframe 2. In cooperation with each other, the upper liner 5 mounted onthe upper frame and the lower liner mounted via the support cone 4 onthe main shaft 3 define a crushing chamber 7 wherein the material to becrushed is fed from above the crusher.

To the lower frame is adapted a drive shaft 8 serving to actuate theeccentric shaft 9. Respectively, to the eccentric shaft is made a boreinclined in regard to the center axis of the crusher chamber so as toaccommodate the main shaft 3 therein. Then, the rotation of theeccentric shaft by the drive shaft in the interior of the crusher framecauses the main shaft inserted in the bore of the eccentric shaft toperform an oscillatory motion.

The crusher setting 11, which is defined as the smallest mutual distancebetween the outer liner and the inner liner, is adapted adjustable byvirtue of pumping a hydraulic medium into the cavity remaining betweensetting control piston 10 and lower frame 1.

The position of support surfaces of the crusher's liners in regard toeach other is monitored by a setting sensor 14 by means of which theheight of the control piston 10 relative to the lower frame 1 isdetermined. Knowing this setting, mathematical means can be applied todetermine the position of the support cone 4 acting as the supportsurface of the inner liner 6 relative to the upper frame 2 acting as thesupport surface of the outer liner 5. Wear sensors 12, 13 placed in thepositions of the liners shown in the diagram monitor the erosion of thewearing parts. Measurement signals from these sensors are transmitted tothe crusher's setting control system described in conjunction with FIG.4 in more detail later in the text.

The main components of the crusher construction shown in FIG. 2 are aframe 14, a bowl 15, a main shaft 3, a support cone 4, an outer liner 5,an inner liner 6, a crushing chamber 7, a drive shaft 8, an eccentricshaft 9, a control motor 16 and a setting adjustment ring 17. On thebowl acting as the support surface for the outer liner is mounted theouter liner, while on the support cone acting as the support surface ofthe inner liner is mounted the inner liner, whereby the two linersdefine a crushing chamber wherein the material to be crushed is fed fromabove the crusher.

Drive shaft 8 serving to actuate eccentric shaft 9 is adapted to thelower frame. Respectively, to the eccentric shaft is made a boresuitable for accommodating therein the main shaft 3 that is mountedfixedly on the crusher frame. Then, the rotation of the eccentric shaftby the drive shaft about the crusher main shaft causes the support conemounted in bearings on the eccentric shaft to perform an oscillatorymotion.

The crusher setting is adjustable by way of rotating the bowl with thecontrol motor, whereby the bowl is elevated or lowered along the threadsof the setting adjustment ring.

The position of the support surfaces of the crusher liners relative toeach other is monitored based on the number of revolutions performed byeither the control motor or the bowl itself or, directly, from theheight position of the bowl. Wear sensors 12, 13 mounted on the crusherliners at locations shown in the diagram monitor the wear of the wearingparts. The measurement signals delivered by these sensors aretransmitted along with the height position signal of the supportsurfaces to the setting control system of the crusher described inconjunction with FIG. 4 in more detail later in the text.

The impact crusher shown in FIG. 3 comprises a frame 18, a rotor 19, arotor shaft 20, breaker bars 21, breaker plates 22, breaker plate shafts23, breaker plate adjustment rods 24 and breaker plate wearing parts 25.The rotor equipped with breaker bars is mounted on the crusher frame viathe rotor shaft. The breaker plates are solidly attached to the crusherframe at their one end by the breaker plate shaft and at their other endin an adjustable fashion by the breaker plate adjustment rods. Thebreaker plate surfaces are covered by wearing parts.

In the operation of an impact crusher, the material to be crushed is fedinto the crusher via an opening made in the crusher frame 18, wherefromthe aggregate material either rolls or falls onto the rotating breakerrotor 19. The rotor is equipped with breaker bars 21 that throw thematerial being crushed against the breaker plates 22. The crushing ofthe infeed material takes place at the impact of the aggregate materialon the breaker bars of the rotor or on the breaker plates of the crusherframe or by the collision of the aggregates against each other. Latestin the gap between the last breaker plate in the travel direction of theaggregate material and the breaker bars of the rotor will be crushed amajor portion of those material particles that when reaching this pointare still larger than the breaker gap setting. The impact crusher shownin the diagram is equipped with three breaker plates, whereby the sizeof the aggregate material being crushed is comminuted stepwise at eachone of the breaker plates into a smaller size equal to the gap settingat a given breaker plate. One end of the breaker plates is solidlyconnected to the crusher frame by the breaker plate shaft 23, while theother end of the breaker plates is connected via the breaker plateadjustment rod 24, each one of the rods serving to individually adjustthe setting of its breaker plate. The position of the last breaker platein the travel direction of the material being crushed determines thefinal gap setting 11 of the entire crusher. The outer surfaces of thebreaker plates are equipped with breaker plate wearing parts 25 thatserve as a breaker liner in cooperation with the breaker bars of therotor.

The setting sensor 14 of the crusher is mounted on the adjustment rod ofthe last breaker plate in the travel direction of the material beingcrushed that controls the final gap setting of the entire crusher. Thissensor delivers the setting signal of the adjustable support surface ofthe wearing part, that is, indicates the position of the breaker plate.The wear sensor(s) 12 of the wearing parts of a breaker plate aremounted on the wearing parts of the breaker that define the setting ofthe crusher. This wear sensor indicates the amount of erosion that hasoccurred in the wearing parts of the crusher. Respectively, the wearsensors 13 mounted on the breaker bars of the rotor indicate the wearthat has occurred in the breaker bars of the rotor. The measurement datadelivered by these sensors is transmitted to the crusher setting controlsystem described in conjunction with FIG. 4 in more detail later in thetext.

As shown in FIG. 4, the frame of the jaw crusher shown therein comprisesa front frame 26, a rear frame 27 and side plates 28 connecting theframes. The crushing cavity is defined by a fixed jaw 29 mounted on thefront frame, a moving jaw 30 connected to a pitman 31 and the sideplates of the jaw crusher. The oscillation of the pitnan is actuated byan eccentric shaft 32 mounted eccentrically in bearings on both thepitman and the crusher side plates in cooperation with a flywheel 33that is coupled to the eccentric shaft and is driven by externalmachinery. The gap width of the jaw opening known as the crusher settingis adjusted by changing the position of setting adjustment wedges 35that via a toggle plate 34 control the crusher setting 11 which is thegap width between the lower edge of the movable jaw and the fixed jaw.

To the lower portions of both the fixed jaw and the movable jaw areadapted wear sensors 12, 13 capable of sending such measurement signalsthat the crusher's automatic control system 36 can based thereon monitorthe wear of the jaws. The crusher's setting adjustment means areequipped with position sensors 14 capable of transmitting such positioninformation that the automatic control system can based thereondetermine the distance of the moving jaw support surface from the fixedjaw support surface. Based on the information submitted by the sensors,the control system can then determine in real time the actual setting ofthe crusher and the change therein due to wear, whereupon the controlsystem is able to maintain the crusher setting at a constant value byvirtue of adjusting the setting adjustment wedges according to thedetected wear of the jaws.

In FIG. 5 is shown the structure of a wear sensor 37 embedded in a wearpart 38 to be monitored, wherein the erosion takes place on the surfaceindicated by an arrow in the diagram.

The wear sensor is comprised of a network of resistors 39, wherefrom theresistors are eroded away from the resistor network as the sensor isworn along with the erosion of the wearing part being monitored. Havingthe isolated terminal of the resistor network connected to a constantvoltage supply, the current through the resistor network can be computedfrom the following equation:I=U/R,where

-   -   U=voltage, and    -   R=overall resistance of resistor network.

With the erosion of the wearing part, the overall resistance of thesensor changes according to the following equation:1/R=1/R ₁+1/R ₂+ . . . +1/R _(n)

whereby also the current through the sensor changes. Knowing the overallresistance of the resistor network and the detected change therein withthe truncation of the network, the amount of erosion in the wearing partcan be determined accurately by measuring the current passing throughthe sensor.

As to the function of the sensor shown in FIG. 5, proper selection ofinsulation material for the wear sensor is a vital issue. With regard tothe insulation material selection, it is important to know the physicalproperties of the infeed material being crushed and the material of thewearing part. In an ideal case the sensor insulation material isselected to exhibit entirely identical erosion properties with thewearing part, whereby the infeed material causes erosion at entirelyidentical rates in both the wearing part proper and the wear sensorembedded therein. This situation, however, is hardly ever attained inpractice inasmuch as the wear sensor invariably tends to be of either aharder and more brittle or, alternatively, of a softer and hence lesswear resistant material than the wearing part proper, whereby there isthe risk of abrupt sensor breakage/crushing or, respectively, rapid wearof the sensor.

In situations preferredly requiring an extremely hard sensor, itsinsulation material may generally be selected from the group of ceramicmaterials, for instance, that are usually only suitable for use as ahard-surface coating. One of such coatings is, e.g., thermally sprayedaluminum oxide. Under certain operating conditions the most advantageouschoice may be a ceramic insulator made from an oxide powder bonded witha binder. As a result, a local breakage in this type of sensor does notcause a larger damage to the sensor. In other situations not primarilyrequiring a hard- surfaced sensor, the sensor may be made using aresilient insulation material such as a composite polymer material.

Irrespective of the insulation material selected, the sensor element isadvantageously always made thin, whereby the impacts inside thecrusher/breaker cannot cause a breakage of the sensor deeper than theeroded surface of the wearing part and, conversely, a projecting portionof the sensor will soon break down to the surface level of the wearingpart if the erosion rate of the wearing part happens to be faster thanthe erosion rate of a hard-surfaced sensor.

In FIG. 6 is shown an exemplary embodiment of the adaptation of aself-contained ultrasonic sensor 40 in a wearing part of a crusher. Thistype of sensor system can be implemented using only a single sensor byvirtue of embedding the sensor in the most wear-prone position of thewearing part or, alternatively, embedding a plurality of sensors indesired positions on the wearing part. When using self-containedultrasonic sensors, the sensors are attached with threaded means orusing a separate sensor mounting substrate adhered with the help of ajoining compound tightly and orthogonally on the rear side of thewearing part. In operation, the sensor emits into the body of thewearing part an ultrasonic wavefront that is reflected from the oppositesurface of the wearing part thus allowing the thickness of the wearingpart at the monitored point to be determined.

In FIG. 7 is shown an exemplary embodiment of the placement of analternative type of ultrasonic sensor on the wearing part of a crusher.Herein one edge of the wearing part is equipped with an ultrasonictransmitter 41 and on the opposite edge of the wearing part is mountedan ultrasonic receiver 42. This kind of sensor arrangement, possibly incombination with an intelligent sensor or an algorithm programmed in thesoftware of the control system, facilitates the determination of thenarrowest point of material thickness between the sensors.

Obviously, the ultrasonic sensors shown in FIGS. 6 and 7 can be replacedby sensors based on newer and more advanced ultrasonic sensortechnologies. One of these alternatives is the so-called MEMS technologyand sensors based thereon like detectors of acoustic emissions. Thesekinds of sensors are capable of measuring simultaneously both thematerial thickness and phenomena possibly undesirably occurring thereinsuch as increase of cracks, permanent deformations, etc.

Additionally, all of the above-described sensors, as well as other kindsof sensors used in a control system according to the invention, mayintegrally incorporate both a self-contained power supply and an RFtransmitter. In this fashion the sensor can be constructed into aself-contained entity capable of sending the measurement signalwirelessly to the crusher's control system located exterior to thecrusher.

These kinds of sensors adapted externally mountable on the surface ofthe crusher's wearing parts allow the sensor to be readily transferredonto a new wearing part in conjunction with the replacement of thewearing part. Furthermore, a single sensor is sufficient for monitoringa plurality of variables characterizing the usability of a wearing partin a crusher.

In FIG. 8 is shown an exemplary embodiment of the placement ofstrain-gage type wear sensors on the wearing part of a crusher. Herein,the use of strain gage elements 43 as the wear sensor on a crusherwearing part is based on the fact that while the erosion of a wearingpart causing the thinning thereof results only in a minor deformation,eventually the progressive erosion allows the rear side of the wearingpart to become increasingly convex or concave. This deformation can bemeasured at a very high accuracy using a strain gage element ofsufficient length. Moreover, a strain gage element permits simultaneousmeasurement of forces imposed on the wearing part during crushing.

Furthermore, product identification technology may readily be integratedwith measurement circuitry based on strain gage sensors. Herein, amicrocontroller 44 or the like unit required in conjunction with straingage sensors for analysis of the measurement signal can also incorporatean ID code of the wearing part. This identification information is theneasy to transmit along with the measurement data to the crusher'sautomatic control system over either a wired or wireless connection. TheID circuit may also be implemented using such technology thatfacilitates reading the ID code with the help of, e.g., a hand-heldscanner suitable for wireless interrogation at a distance of a fewmeters from the crusher. The ID information may also be transmitted at aclose range using a Bluetooth circuit. Using modern technology, it ispossible to package the sensor amplifier, ID code circuit and theBluetooth circuit in the size of half a credit card. Then, theidentification information can be read using, e.g., a cellular phone asthe reader.

Such an easy retrieval of component identification information gives thecrusher operator a substantial aid in the definition and ordering of arequired spare part as to its category and type.

The ID code of a wearing part may also be complemented with additionalinformation about the wearing part that may be useful at later stages ofthe service life of the wearing part. For instance, the ID code may becomplemented with such information on the metal alloy composition of thewearing part that can be utilized in the recycling of the wearing part.Other like information includes, e.g., the dimensions, weight andsimilar data of the wearing part.

In FIG. 9 is shown an exemplary embodiment of the placement ofstrain-gage type wear sensors operating as a fully self-containedentity. The sensor entity comprises a strain gage sensor 43, an energycapturing antenna 45, an integrated intelligent sensor circuit 44 and anRF antenna 46.

The measurement data obtained from the strain gage sensor 43 is gatheredby the intelligent sensor circuit 44 that transmits the gatheredinformation via the RF antenna 46 wirelessly to the crusher's controlsystem situated exterior to the crusher. The operating energy of theintegrated sensor package is captured with the help of an antenna 45from an electromagnetic field surrounding the crusher unit. Thefunctions of the intelligent sensor circuit comprise the conditioning ofthe operating energy captured by the antenna, processing of themeasurement data obtained from the strain gage sensor and transmissionof the processed information via the RF antenna. Additionally, theintelligent sensor circuit is programmed to include the ID code of thewearing part proper.

In this fashion, combination of radio-frequency (RF) technology withstrain-gage technology permits an integrated sensor entity to beconfigured into a single self-adhesive tag. The units of the sensorassembly may also be comprised of separate blocks that are adhered byglueing to the rear surface of the wearing part. After installation, theseparate blocks are connected to a common intelligent sensor circuit.

By way of mounting the sensor assemblies of the above-described kind onthe rear sides of the opposed wearing parts in a crusher, vitalinformation can be submitted to the control system of the crusher foraccurate setting determination of the crusher, whereby the crusher maybe controlled so as to maintain its setting at a desired valueirrespective of the erosion of its wearing parts.

The invention is not limited to any given type of crusher, but insteadmay be adapted to all kinds of crushers equipped with wearing parts.

Further, the invention is not limited to the sensor constructionsdescribed above, but instead a crusher adjustment and control systemaccording to the invention may utilize all types of such sensors thatare capable of submitting sufficient information as input signals to thecontrol system.

1. A method for measuring and monitoring the setting of a crusher duringthe crushing process, in which method the erosion of the wearing partsof a crusher is measured and the setting of a crusher is adjusted basedon the measurement result so as to maintain the setting at apredetermined value irrespective of the erosion of the wearing parts,characterized in that the measurement data indicating the amount oferosion in said wearing parts of the crusher is transmitted wirelesslyto the exterior side of the crusher.
 2. The method of claim 1,characterized in that a wearing part replacement order is automaticallyissued as soon as the measurement data indicating the amount of erosionin the wearing parts reaches a predetermined threshold value.
 3. Anapparatus for measuring and monitoring the setting of a crusher duringcrushing, the apparatus comprising at least one wear sensor mounted on acrusher liner, means for adjusting the crusher setting, at least onesensor mounted on said means for adjusting the crusher setting and anautomatic control system of the crusher, in which apparatus saidcrusher's automatic control system receives a first input signal from awear sensor mounted on at least one liner of the crusher, said firstinput signal being suitable for determination of amount of erosion insaid liner, and a second input signal from said sensor mounted on thesetting adjustment means of the crusher, said second input signal beingsuitable for determination of the relative position of the supportsurfaces of the crusher's wearing parts, whereby the crusher's automaticcontrol system is able based on both input signals to adjust the crushersetting so as to maintain the setting of the crusher in itspredetermined value irrespective of the erosion of the wearing part,characterized in that at least one wear measurement sensor is mounted oneach one of the crusher liners, and that said sensors are equipped withmeans for transmitting the measurement data wirelessly to the exteriorside of the crusher.
 4. The apparatus of claim 3, characterized in thatthe crusher's automatic control system includes means for receiving saidwirelessly transmitted data.
 5. The apparatus of claim 3 or 4,characterized in that said sensors are equipped with means forgenerating the electrical energy required for the operation of thesensors.
 6. The apparatus of claim 5, characterized in that said meansfor generating the electrical energy required for the operation of thesensors comprise elements suitable for converting kinetic energy intoelectrical energy.
 7. The apparatus of claim 5, characterized in thatsaid means for generating the electrical energy required for theoperation of the sensors comprise a piezoelectric device.
 8. Theapparatus of claim 5, characterized in that said means for generatingthe electrical energy required for the operation of the sensors comprisemeans for generating energy from an electromagnetic field surroundingthe crusher.
 9. A sensor suitable for use in any one of the apparatusesdisclosed in claims 3-8 for measuring the amount of erosion in thewearing parts of a crusher, characterized in that the wearing portion ofthe sensor comprises a resistor network formed by a plurality ofresistors in parallel, whereby the resistors along with the erosion ofthe wearing part in the crusher become erosively disconnected from theresistive network thus changing the overall resistance of the circuitfeeding current to the wear sensor, whereby a measurement signalproportional to the amount of erosion in the wearing part is generated.10. A sensor suitable for use in any one of the apparatuses disclosed inclaims 3-8 for measuring the amount of erosion in the wearing parts of acrusher, characterized in that the wearing portion of the sensorcomprises a resistor network formed by a plurality of resistors inseries, whereby the resistors along with the erosion of the wearing partin the crusher become erosively disconnected from the resistive networkthus changing the overall resistance of the circuit feeding current tothe wear sensor, whereby a measurement signal proportional to the amountof wearing part erosion is generated.
 11. A sensor suitable for use inany one of the apparatuses disclosed in claims 3-8 for measuring theamount of erosion in the wearing parts of a crusher, characterized inthat the sensor is implemented such that the sensor utilizes acousticwaves.
 12. The sensor of claim 11, characterized in that the sensor isan ultrasonic sensor.
 13. The sensor of claim 11, characterized in thatthe sensor is implemented using MEMS technology in the sensorconstruction.
 14. The sensor of claim 13, characterized in that thesensor is an acoustic emission detecting sensor.
 15. The sensor of anyone of claims 11-14, characterized in that the sensor incorporatesseparate means for emitting and receiving a sensing impulse.
 16. Asensor suitable for use in any one of the apparatus disclosed in claims3-8 for measuring the amount of erosion in the wearing parts of acrusher, characterized in that the sensor is based on a strain gageelement.
 17. The sensor of claim 16, characterized in that the sensor isalso capable of measuring forces imposed on the wearing part duringcrushing.
 18. The sensor of claim 16 or 17, characterized in that thesensor incorporates means for storing and wirelessly transmitting theidentification data of the wearing part.
 19. The sensor of any one ofclaims 16-18, characterized in that RF technology is used in theimplementation of at least a portion of the sensor elements.